Starting April 10, the news and culture publisher will require people using ad-blocking software to pay $3.99 a month or $39.99 a year for an ad-free version or turn off their ad blockers and view an ad-supported version of the site. The Atlantic planned the move to follow its converting the site to https. Publishers have been undertaking that process to provide secure connections for visitors and in anticipation of Google giving preference to https sites in its search results.

The Atlantic has been preparing ad blockers for this move since October, when it offered that choice in a message window. It was a soft wall, though, as ad blockers could continue visiting the site for free if they closed the window. Now, that escape hatch is going away.

Lately, publishers have been taking the brute-force approach to ad blockers or asking readers to pay up to help support the heavy cost of digital media. This move by the Atlantic isn’t so much geared toward getting readers to pay — just half of 1 percent of the ad blockers opted to pay up since October, and The Atlantic is pushing subscriptions to its magazine in other ways.

Slate editor-in-chief Julia Turner last week wrote a piece on the site asking readers to whitelist the site, while revealing it lost $1.5 million to $2 million from ad blocking. Slate does not block ad blockers from accessing content, however. The Atlantic estimates that ad blocking cost it $3.4 million in 2016.

Ten to 12 percent of visitors to The Atlantic have ad blockers installed. And while the percentage of people ad blocking has leveled off, it’s not likely to go away long-term, given that young people are more likely to ad block.

“To me, starting the conversation and helping them understand the value exchange is important,” said Kim Lau, svp of digital and head of business development at the Atlantic. “We have to start that conversation about how we make our money. We need people to understand there is a real dependency on advertising. We have journalists we need to continue to pay to do great journalism that’s critical at this time.”

The Atlantic fully expects 60 percent of those ad blockers to abandon the site when presented with the message. There’s some anxiety about that. But as Lau sees it, those people aren’t contributing financially to the site, so losing them won’t have a big financial impact anyway.

The publication has been taking on ad blockers for more than a year, starting with messages requesting they whitelist the site. Some publishers have circumvented ad blockers and served ads to those people anyway, but The Atlantic didn’t go that route, lest it upset people who already expressed a clear preference not to see ads.

How publishers communicate to ad blockers has proved to make a big difference in their success in getting them to whitelist a site. Making sure the language was right was the biggest issue for The Atlantic for the past several months. A lot of people didn’t realize they had multiple ad blockers installed or didn’t understand how to whitelist the site, Lau said.